TECHNICAL FIELD
[0001] The present invention relates to a control technique for transferring data read from
a storage medium to a temporary storage unit.
BACKGROUND ART
[0002] A reproducing apparatus that reads data stored in a storage medium and reproduces
the data is widely used for reproducing music or video.
[0003] For example, a reproducing apparatus that reproduces video, such as a movie stored
in a DVD, a reproducing apparatus that reproduces a music stored in a CD, and a reproducing
apparatus that supports various types of storage media, such as DVD and CD, and reproduces
a music, a movie or the like stored in the storage media are widely known.
[0004] Such a reproducing apparatus, reading a large amount of digital data, such as a music
or movie, from a storage medium and performing reproduction processing, including
decoding, on the digital data, needs to overcome noise generated due to high-frequency
driving of a reading means for reading digital data (e.g., an optical pickup) and
a noise generated due to processing of digital data as high frequency signal.
[0005] In order to overcome noise generated when data is read from a storage medium, an
optical disc apparatus has been proposed that shields radiated emission of high frequency
signal generated due to driving of an optical pickup housed in a DVD unit, by magnetically
shielding the radiated emission of high frequency signal at a portion of the front
and bottom surfaces and a portion of the both sides and rear surfaces of the DVD unit
(see the patent document 1).
[0006] In order to overcome noise generated due to internal processing of an apparatus,
a DVD apparatus has been proposed that significantly reduces radiated emission by,
in a configuration in which a circuit board is divided into a digital circuit board
and a power supply board that are placed on both sides of an optical disc loader,
changing how to divide the ground pattern of the digital circuit board and placing
a filter on the digital circuit board adjacent to a connector (see the patent document
2).
[0007] In order to overcome a problem in which, when a control signal, such as a tracking
error signal output from an optical pickup, includes noise due to a high frequency
component, a tracking servo control unit receiving the amplified control signal becomes
unstable in position control of the optical pickup, an optical disc apparatus has
been proposed that determines the type (application, country of manufacture, manufacturer
and the like) of an optical medium applied to the optical disc apparatus, and, when
the optical medium is a specified optical medium, activates a frequency characteristic
change circuit to change the frequency characteristic to be applied to a control signal
input to a servo IC so that the high frequency component of the control signal will
be attenuated, thereby reducing high frequency noise included in the control signal
(see the patent document 3).
[0008] In order to provide an information recording/reproducing apparatus that can record/reproduce
information to/from plural types of recording media without increasing the amount
of hardware, an information recording/reproducing apparatus has been proposed that
determines the type of a loaded optical disc (e.g. , DVD or BD or the like) and changes
the configuration of plural logic circuits in a reconfigurable circuit according to
a program corresponding to the type of the optical disc to configure a modulation/demodulation
circuit and an error correction circuit corresponding to the type of the optical disc,
which allows configuration of a different type of the modulation/demodulation circuit
and the error correction circuit depending on the various types of optical discs without
increasing the amount of hardware (see the patent document 4) .
[0009] In order to provide an optical disc apparatus that controls any type of optical disc
using the same CPU or optical disc controller and provides high performance and high
reliability, an optical disc controller has been proposed that includes: a rewritable
memory for storing information necessary for recording/reproducing of an optical disc;
a determination unit for determining the type and sub-type of an optical disc; a search
unit for searching a region in which the control information for the optical disc
is recorded, based on the determination result given by the determination unit; a
reproduction unit for reproducing the control information recorded in the region searched
by the search unit; and a memory control unit for changing memory allocation based
on at least one of the determination result and the control information reproduced
by the reproduction unit (see the patent document 5).
Patent document 1
JP-A-2002-140887
Patent document 2
JP-A-2005-18849
Patent document 3
JP-A-2000-67441
Patent document 4
JP-A-2007-141310
Patent document 5
JP-A-2003-51152
DISCLOSURE OF INVENTION
[0010] As described above, a reproducing apparatus, such as an optical disc apparatus, performs
read processing of reading a large amount of data, such as a music or movie, from
a storage medium and reproduction processing of reproducing the read data, in which,
at present, the speed of the reproduction processing is slower than that of the read
processing.
[0011] Specifically, whereas the processing of reading data from a storage medium can be
quickly performed easily, the reproduction processing includes a complicated and time-consuming
processing, such as data decoding, and also includes a processing of reproducing a
music or movie in accordance with the speed of outputting to a speaker or display,
which takes a certain amount of time.
[0012] Accordingly, the reproducing apparatus, including a temporary storage unit for temporarily
storing data to be reproduced, reads data from the storage medium, then transfers
and stores the data in the temporary storage unit, and then sequentially reads and
reproduces the data stored in the temporary storage unit.
[0013] The present invention is made in the light of the event in which increase in the
number of types of storage media that the reproducing apparatus can support causes
noise also in transferring data to the temporary storage unit.
[0014] Specifically, the rate of transferring data to the temporary storage unit is previously
constant, however, when the amount of data read from the storage medium is small (for
example, the amount of data read from a CD is significantly smaller than that from
a DVD), clusters of data are transferred to the temporary storage unit intermittently
(e.g., at intervals of one second), as shown in the left of Fig. 3(a).
[0015] As a result, this intermittent transfer of data causes a large amount of current
to instantaneously and repeatedly flow, thereby generating a high-intensity radio
wave as noise.
[0016] However, no invention has been made to overcome the above-described problem, and
no technique has existed to effectively manage noise due to transferring data to the
temporary storage unit.
[0017] As a common practice, one method may be to cover a noise-generating portion with
a shield plate. However, this method increases the number of parts, leading to a larger
apparatus, a more complicated structure, and a higher product cost, so this method
is not an effective solution.
[0018] In view of the above problem, it is an obj ect of the present invention to provide
a transfer control apparatus that suppresses or prevents noise generation in transferring
data to a temporary storage unit.
[0019] In order to achieve the above object, the present invention is embodied in a transfer
control apparatus used for a reproducing apparatus.
[0020] Specifically, the transfer control apparatus in accordance with the invention is
a transfer control apparatus for transferring data read from a storage medium to a
temporary storage unit, including: a determination unit for determining the type of
the storage medium from which data is read; a data transfer unit for transferring
data read from the storage medium to the temporary storage unit; and a transfer rate
change unit for changing the data transfer rate of the data transfer unit according
to the type of the storage medium determined by the determination unit to level the
data transfer.
[0021] According to the transfer control apparatus in accordance with the invention, the
determination unit determines the type of the storage medium, then according to the
determined type of the storage medium, the transfer rate change unit changes the data
transfer rate of the data transfer unit for transferring data read from the storage
medium to the temporary storage unit to level the data transfer to the temporary storage
unit.
[0022] For example, when the amount of data to be transferred is reduced (e.g., the storage
medium is changed from a DVD to a CD), if the data transfer rate remains high as with
a DVD, clusters of data are transferred to the temporary storage unit intermittently
as described above. However, reducing the data transfer rate provides a leveled state
in which a certain amount of the data is constantly transferred with time. Thus, leveling
the data transfer to the temporary storage unit suppresses or prevents noise generation
due to the intermittent transfer of data causing a large amount of current to instantaneously
and repeatedly flow.
[0023] Note that, even when the amount of data transfer is not always constant with time,
if the amount of data transfer varies mildly with time (without rapid change), noise
generation due to the data transfer may be suppressed or prevented.
[0024] Thus, as used herein, the term "level," "leveling" and "leveled" also refers to mild
change in the amount of data transfer with time, so the data transfer rate may be
changed so that such extent of change may be tolerated.
[0025] Note that, for example, since the larger (smaller) the data storage capacity of the
storage medium is, the larger (smaller) the amount of data may be read from the storage
medium, the data transfer rate may be changed according to the type of the storage
medium such that the larger (smaller) the data storage capacity of the storage medium,
the higher (lower) the data transfer rate is.
[0026] Furthermore, separately from the data storage capacity, since a data reading scheme
and data reading rate are defined for each type of storage medium, the leveling may
be achieved by changing the data transfer rate according to data reading rate defined
for each type of storage medium.
[0027] Furthermore, the invention is also embodied as a transfer control apparatus for achieving
the above object.
[0028] Specifically, the transfer control apparatus in accordance with the invention is
a transfer control apparatus for reading data stored in a storage medium and reproducing
the data, including: a read unit for reading data from the storage medium; a determination
unit for determining the type of the storage medium from which data is read by the
read unit; a data transfer unit for transferring data read from the storage medium
to the temporary storage unit; and a transfer rate change unit for changing the data
transfer rate of the data transfer unit into a preset transfer rate corresponding
to the type of the storage medium according to the type of the storage medium determined
by the determination unit.
[0029] Thus, according to the transfer control apparatus in accordance with the invention,
the data transfer to the temporary storage unit by the data transfer unit at a preset
transfer rate corresponding to the type of the storage medium levels the data transfer
to the temporary storage unit as with the transfer control apparatus described above,
which suppresses or prevents noise generation due to the intermittent transfer of
data causing a large amount of current to instantaneously and repeatedly flow.
[0030] Note that, in the transfer control apparatus in accordance with the invention, the
preset transfer rate corresponding to the type of the storage medium may be set so
that the smaller the data storage capacity of the storage medium is, the lower the
data transfer rate is, and also, so that the larger the data storage capacity of the
storage medium is, the higher the data transfer rate is.
[0031] Accordingly, for example, in contrast to the above, when the amount of data to be
transferred is increased (e.g., the storage medium is changed from a CD to a DvD),
if the data transfer rate remains low as with a CD, the data transfer to the temporary
storage unit may get delayed and cause a problem for subsequent reproduction processing.
However, increasing the data transfer rate allows data read from a DVD to be quickly
transferred to the temporary storage unit.
[0032] Furthermore, in the transfer control apparatus in accordance with the invention,
the rate of data transfer to the temporary storage unit may be preset according to
a data reading scheme and data reading rate defined for each type of storage medium
to suppress or prevent noise generation in transferring data.
[0033] Furthermore, in the transfer control apparatus in accordance with the invention,
the plural read units may be provided according to the types of storage media.
[0034] For example, with the plural read units each corresponding to a different storage
medium, the determination unit can determine the type of the storage medium from which
data is read, according to which of the read units is activated.
[0035] Furthermore, in the transfer control apparatus in accordance with the invention,
the determination unit can determine the type of the storage medium from which data
is read by the read unit, based on an operation input from a user.
[0036] For example, in the transfer control apparatus that is configured to be able to reproduce
data of a storage medium that has been already loaded into the reproducing apparatus
(e.g., a hard disk apparatus or memory card) when a user performs an operation input
to specify the storage medium, the determination unit can determine the type of the
storage medium from which data is read, based on the operation input.
[0037] Furthermore, in the transfer control apparatus in accordance with the invention,
the read unit may be an optical pickup for optically reading data from an optical
disc as a storage medium, and the determination unit may determine the type of the
optical disc based on changing of the optical pickup.
[0038] For example, in the transfer control apparatus having a disc loader (read unit) including
an optical pickup for BD and an optical pickup for DVD that is used for reading from
a BD and also from a DVD, the determination unit may determine whether an optical
disc is a BD or DVD, based on changing of the optical pickup by the disc loader.
[0039] The invention is configured as a transfer control apparatus that can reproduce at
least two types of storage media from various storage media including a Blu-ray Disc
(BD), digital video disc (DVD), compact disc (CD), memory card and hard disk apparatus
(HDD).
[0040] Furthermore, the transfer control apparatus in accordance with the invention may
also be configured as a recording/reproducing apparatus also capable of recording
data, such as a music or video, to a storage medium.
[0041] Furthermore, each functional unit of the transfer control apparatus in accordance
with the invention may be configured by executing a program using computer hardware
including a processor and a memory, or may be configured as a hardware apparatus using
an electric circuit.
[0042] According to the invention, noise generation in transferring data may be suppressed
or prevented by transferring data to the temporary storage unit at a data transfer
rate according to the amount of data to be transferred.
[0043] This can eliminate the need for providing a shield plate, which can provide a transfer
control apparatus and a reproducing apparatus using the transfer control apparatus
that prevents failure due to noise generation without leading to a larger apparatus,
a more complicated structure, and a higher product cost.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044]
Fig. 1 shows an appearance of a reproducing apparatus in accordance with an embodiment
of the invention;
Fig. 2 illustrates a configuration of the main part of the reproducing apparatus in
accordance with the embodiment of the invention;
Fig. 3 illustrates a data transfer state in accordance with the embodiment of the
invention; and
Fig. 4 illustrates changing of a data transfer rate in accordance with the embodiment
of the invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0045] The present invention is specifically described based on an embodiment shown in the
drawings.
[0046] As shown in Fig. 1, a reproducing apparatus 1 using a transfer control apparatus
in accordance with the embodiment is connected to a television set 2 and outputs a
reproduced video or music through a display or speaker of the television set 2.
[0047] The reproducing apparatus 1 includes: a disc loader (read unit) 4 for loading an
optical disc 3, such as BD, DVD and CD; a card reader (read unit) 6 for loading an
SD memory card 5; and buttons (operation part) 7 for receiving an operation input
from a user. Note that an HDD apparatus may also be connected to the reproducing apparatus
1.
[0048] That is, the reproducing apparatus 1 includes the read unit 4 commonly used for three
types of storage media 3, such as BD, DVD and CD, and the read unit 6 used for a storage
medium (SD memory card). When the HDD apparatus is connected, the reproducing apparatus
1 includes an interface as a read unit for receiving data output from the HDD apparatus.
[0049] Fig. 2 shows a functional configuration included in the reproducing apparatus 1 for
reading data from a storage medium and reproducing the data.
[0050] The reproducing apparatus 1 includes: a processing unit 10 for controlling read processing
and reproduction processing of data; a double data rate random access memory (DDRRAM)
20 used as a temporary storage memory for the processor; and a decoder 30 for decoding
data.
[0051] The processing unit 10 consists of a semiconductor device referred to as MAIN IC
including: a read control unit 11 relating to data read control as a front end part
(FE) ; and a reproduction control unit 12 relating to data reproduction control as
a back end part (BE).
[0052] In response to loading the storage medium 3 or 5 or both into the read unit 4 or
6 or both, the read control unit 11 controls the appropriate read unit to read digital
data, such as a music or movie, recorded in the storage medium. In this control, a
type determination unit 13 included in the read control unit 11 determines the type
of the storage medium from which the digital data is read.
[0053] The disc loader 4 selects an optical pickup according to the type of the loaded optical
disc 3. For example, the disc loader 4 selects a blue laser optical pickup for BD,
a red laser optical pickup for DVD, and a near infrared laser optical pickup for CD.
The type determination unit 13 receives from the disc loader 4 a signal indicative
of the type of the selected optical pickup to determine the type of the optical disc
from which data is read.
[0054] Note that the way in which the type determination unit 13 determines the type of
the optical disc from which data is read is not limited. For example, the type determination
unit 13 may determine the type of the optical disc from which data is read, based
on a user input to the operation part (buttons) 7 specifying the type of the optical
disc loaded into the disc loader 4.
[0055] Or the type determination unit 13 may determine the type of the recording medium
from which data is read, based on the fact that the SD memory card 5 is loaded into
the read unit 6 dedicated to an SD memory card. In this embodiment, the type determination
unit 13 determines that the recording medium from which data is read is an SD memory
card, based on a user input to the operation part (buttons) 7.
[0056] This allows a user to keep the SD memory card 5 storing a music or the like loaded
in the reproducing apparatus 1 and input an operation to reproduce the data in the
SD memory card 5 at any time.
[0057] The reproduction control unit 12, including a data transfer unit 14 and a transfer
rate change unit 15, performs control for outputting data read from the storage medium
3 or 5 or both to the decoder 30, utilizing the memory 20 as a temporary storage.
[0058] The data transfer unit 14 performs processing of outputting and storing data read
from the storage medium 3 or 5 or both in the memory 20 and processing of reading
data stored in the memory 20. The data transfer unit 14 can select the data transfer
rate for the outputting and reading from several rate options as ordered by the transfer
rate change unit 15.
[0059] Based on a type indicating signal input from the type determination unit 13, the
transfer rate change unit 15 outputs a signal to the data transfer unit 14 indicating
a data transfer rate preset according to the type of the storage medium 3 or 5 from
which data is read by the read unit 4 or 6 or both.
[0060] In the transfer rate change unit 15 of the embodiment, several data transfer rates
are preset corresponding to the types of the storage media so that the amount of data
transfer will be leveled with respect to the elapse of time in data transfer to/from
the memory 20. The transfer rate change unit 15 orders the data transfer unit 14 to
change the data transfer rate according to the determined type of the storage medium.
[0061] More specifically, in the transfer rate change unit 15 of the embodiment, the data
transfer rate is preset so that: the smaller (larger) the data storage capacity of
a storage medium, the lower (higher) the data transfer rate; and the lower (higher)
the rate of reading data from the storage medium, the lower (higher) the data transfer
rate, and based on this, several data transfer rates preset so that data transfer
to/from the memory 20 will be leveled are prepared.
[0062] In the configuration of the reproducing apparatus 1, the processing unit 10 including
the determination unit 13, the data transfer unit 14 and the transfer rate change
unit 15 forms a transfer control apparatus for transferring data read from a storage
medium to the memory 20.
[0063] Next, the processing operation of the reproducing apparatus 1 having the above configuration
is described.
[0064] First, when the storage medium 3 or 5 or both is loaded into the read unit 4 or 6
or both and the reproducing apparatus 1 starts reproduction, the read unit into which
the storage medium is loaded reads digital data stored in the storage medium, and
the type determination unit 13 determines the type of the storage medium, under the
control of the read control unit 11.
[0065] Then, the transfer rate change unit 15, informed of the determined type of the storage
medium, orders the data transfer unit 14 to use the transfer rate corresponding to
the determined type. On the other hand, the data transfer unit 14 receives the read
digital data, and transfers and stores the digital data in the memory 20 at the transfer
rate ordered by the transfer rate change unit 15.
[0066] Then, depending on decoding or the like by the decoder 30, the digital data stored
in the memory 20 is read and outputted to the decoder 30. Then, a music or video decoded
by the decoder 30 is presented by the television set 2.
[0067] The transfer rate is ordered by the transfer rate change unit 15 as shown in Fig.
4.
[0068] First, the transfer rate change unit 15 determines the reproduction mode (i.e., type)
of the storage medium from the determination result (step 1). For the mode of reading
digital data from a CD to reproduce, the transfer rate change unit 15 orders the data
transfer unit 14 to use an A-setting data transfer rate (step S2). For the mode of
reading digital data from an SD memory card to reproduce, the transfer rate change
unit 15 orders the data transfer unit 14 to use a B-setting data transfer rate (step
S3). For the mode of reading digital data from a BD or DVD to reproduce, the transfer
rate change unit 15 orders the data transfer unit 14 to use a C-setting data transfer
rate (step S4).
[0069] In this setting, the relation between these data transfer rates is: the A-setting
< the B-setting < the C-setting. For example, the data transfer rate for the mode
of reading digital data from a CD to reproduce (A-setting) is lower than that for
the mode of reading digital data from a BD or DVD to reproduce (C-setting).
[0070] As a result, for example, in reproducing a CD, if the data transfer rate is high
as in reproducing a BD or DVD (C-setting), digital data would be intermittently transferred
to the memory 20 to generate noise, as shown in the left of Fig. 3(a), however, in
this embodiment, the data transfer rate is changed to an appropriate rate for transferring
data read from a CD, so the digital data is transferred to the memory 20 without a
significant change in the amount of data transfer as shown in the right of Fig. 3(a),
which eliminates noise generation.
[0071] Also, in reproducing a BD or DVD, the data transfer rate of the data transfer unit
14 is changed to the C-setting rate appropriate for transferring digital data read
from a BD or DVD as in the above, so the digital data is transferred to the memory
20 at a relatively high rate without a significant change in the amount of data transfer
as shown in Fig. 3(b), which eliminates noise generation.
INDUSTRIAL APPLICABILITY
[0072] The present invention is able to apply to a reproducing apparatus that reads data
from various types of storage media, such as Blu-ray Disc (BD), digital video disc
(DVD), compact disc (CD) and memory card, and transfers the data to a temporary storage
unit in reproduction processing.